Writing in Human Ecology, David Zhang from the University of Hong Kong and colleagues show that warfare frequency in eastern China between 1000 and 1911 A.D. was significantly correlated with temperature oscillations. Comparing 899 wars during that period to historical temperature data, the researchers found that warfare peaked during cold phases.

“Temperature fluctuations directly impact agriculture and horticulture and, in societies with limited technology such as pre-industrial China, cooling temperatures hugely impact the availability of crops and herds,” explained a statement from Springer, publisher of the journal Human Ecology. “In times of such ecological stress, warfare could be the ultimate means of redistributing resources.”

The Human Ecology comes just weeks after U.N. Secretary General Ban Ki-moon said that the unrest in Darfur, Sudan was triggered by global climate change and that similar conflicts may be on the horizon.